Sound suppression device, sound suppression system, and wearable sound device

Abstract

To provide a sound suppression device, a sound suppression system, and a wearable sound device that can suppress broadband noise.SOLUTION: A sound suppression device comprises: a sound sensing device configured to sense sound; and a sound generation device having an air pulse generation device configured to generate multiple air pulses at an ultrasonic pulse rate. The multiple air pulses at the ultrasonic pulse rate form an anti-sound. The anti-sound includes a component configured to suppress the sound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a sound suppression device, a sound suppression system, and a wearable sound device, and more particularly to a sound suppression device, a sound suppression system, and a wearable sound device that can suppress wideband noise. [Background technology]

[0002] Speaker driver and back enclosure are two major design challenges in the traditional speaker industry. It is difficult for a traditional speaker to cover the entire audible frequency range, e.g., 20Hz to 20KHz. To produce wide audible range sound at a desired sound pressure level (SPL), a traditional speaker needs to increase both the radiating / moving surface and the volume / size of the back enclosure. Considering the large size of a speaker that generates wide audible range sound, it is difficult to achieve full-band noise suppression, especially in an open field.

[0003] Furthermore, conventional speakers (e.g., dynamic drivers) produce phase mismatch across the entire audible range. In other words, the phase at low frequencies (as occurs with conventional speakers) is significantly different from the phase at high frequencies. This phase mismatch makes noise cancellation / suppression more difficult to address, which is also a challenge for conventional ANC (active noise canceling).

[0004] Therefore, how to surpass existing technologies is an important issue in this field. Summary of the Invention

[0005] Therefore, the main object of the present application is to provide a sound suppression device, a sound suppression system and a wearable sound device that can suppress wideband noise in order to improve the shortcomings of the prior art.

[0006] One embodiment of the present invention provides a sound suppression device, the sound suppression device including a sound sensing device configured to sense sound; and a sound generating device having an air pulse generating device configured to generate a plurality of air pulses at an ultrasonic pulse rate, the plurality of air pulses at the ultrasonic pulse rate forming an anti-sound, the anti-sound including a component configured to suppress the sound.

[0007] One embodiment of the present invention provides a sound suppression system comprising a plurality of sound suppression devices arranged in an array, each sound suppression device comprising a sound sensing device configured to sense sound and a sound generating device configured to generate reflected sound, the reflected sound being configured to suppress the sound.

[0008] One embodiment of the present invention provides a wearable sound device, the wearable sound device having a sound sensing device configured to sense sound and a sound generating device configured to generate reflected sound, the reflected sound including a component configured to suppress sound, the sound generating device being located outside the ear canal.

[0009] These and other objects of the present invention will no doubt become obvious to those skilled in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a sound suppression device according to an embodiment of the present application;

[0011] [Figure 2] 1 is a schematic diagram of an air pulse generating device according to an embodiment of the present application;

[0012] [Figure 3] 1 shows a schematic diagram of a controller coupled to a sound suppression device of the present application;

[0013] [Figure 4] 1 illustrates a feedback control loop of an embodiment of the present application.

[0014] [Figure 5] FIG. 1 shows a schematic diagram of a sound suppression apparatus disposed within a wearable sound device according to an embodiment of the present application.

[0015] [Figure 6] 1 shows a schematic diagram of a sound suppression apparatus disposed within a wearable sound device according to an embodiment of the present application.

[0016] [Figure 7] 1 shows a schematic diagram of a sound suppression apparatus disposed within a wearable sound device according to an embodiment of the present application.

[0017] [Figure 8] 1 shows a schematic diagram of a sound sensing device and a sound generating device attached around the ear canal according to an embodiment of the present application.

[0018] [Figure 9] 1 shows a schematic diagram of loop gain adjustment and latency adjustment according to an embodiment of the present application;

[0019] [Figure 10] 1 is a schematic diagram of a sound suppression system according to an embodiment of the present application;

[0020] [Figure 11] 1 shows a schematic diagram of an embodiment of a sound suppression system applied to an acoustic screen.

[0021] [Figure 12] 1 shows a schematic diagram of one embodiment of a sound suppression system applied to forming an acoustically isolated space.

[0022] [Figure 13]1 shows a schematic diagram of an office scenario as an application of a sound suppression system according to an embodiment of the present invention;

[0023] [Figure 14] 1 shows a schematic diagram of an aircraft cabin scenario as an application of a sound suppression device / system according to an embodiment of the present invention;

[0024] [Figure 15] 1 shows a schematic diagram of a building scenario as an application of a sound suppression system according to an embodiment of the present invention.

[0025] [Figure 16] 1 shows a schematic diagram of a residential space scenario as an application of a sound suppression system according to an embodiment of the present invention.

[0026] [Figure 17] 1 shows a schematic diagram of a residential space scenario as an application of a sound suppression system according to an embodiment of the present invention;

[0027] [Figure 18] 1 shows a schematic diagram of a seating scenario as an application of a sound suppression device according to an embodiment of the present invention;

[0028] [Figure 19] 1 shows a schematic diagram of a soundwall scenario as an application of a sound suppression device according to an embodiment of the present invention;

[0029] [Figure 20] 1 shows a schematic diagram of the waveforms of sound, echo and ultrasonic air pulses. DETAILED DESCRIPTION OF THE INVENTION

[0030] The contents of U.S. Patent Application Nos. 16 / 125,761, 17 / 553,806 and 18 / 321,759 are incorporated herein by reference.

[0031] U.S. Patent Applications Nos. 16 / 125,761, 17 / 553,806 and 18 / 321,759 disclose APG (Air Pulse Generator) devices that operate under APPS (Air Pressure Pulse Speaker) sound generation principles, whereby audible sounds can be generated by modulating the amplitude of ultrasonic acoustic pulses at ultrasonic pulse rates well beyond the range of human hearing, such that each generated ultrasonic acoustic pulse has an asymmetry relative to the ambient air pressure that is proportional to the amplitude sampled at the ultrasonic pulse rate of the audible sound to be generated.

[0032] The APG device disclosed in U.S. Patent Application No. 18 / 321,759 can be manufactured in small sizes using MEMS technology to generate load sound. In one embodiment, the APG device disclosed in U.S. Patent Application No. 18 / 321,759 measures 5.68 x 5.28 x 0.85 mm 3 The APG device may have L×W×H dimensions of (L: length, W: width, H: height, mm: millimeters) and be capable of generating 78±2 dB SPL (Sound Pressure Level) at a distance of 1 meter over the 10 Hz to 20 kHz frequency range. Note that because the wavelength corresponding to 20 kHz sound is substantially 346 / K = 17.3 mm, a physical implementation of the APG device has L / W / H dimensions that are smaller than the third wavelength λ / 3 of 20 kHz sound. In other words, the dimensions of the APG device (which may be L, W, or H) are less than the wavelength corresponding to the maximum noise frequency of the noise to be suppressed (e.g., the aforementioned 20 kHz). Alternatively, (W+L+H) / 2≦λ / π, where λ is the wavelength corresponding to the maximum noise frequency of the noise to be suppressed.

[0033] Another aspect of the APG device is that it eliminates the need for a back enclosure, which in many conventional speakers is used to contain rear-radiated sound waves to prevent them from canceling each other out. As described in 16 / 125,761 and 18 / 321,759 (and the reference(s) therein), aspects of APPS operation are utilized to make the audible (baseband) radiation from the rear of the APG device (or facing the internal volume of the host device) much weaker than the audible (baseband) radiation from the front of the APG device (or facing the surroundings of the host device). In one embodiment, the rear-radiated waves can be 5 to 50 times weaker than the front-radiated waves, but this is not limiting. In this case, the SPL does not vary significantly even when the front-radiated and rear-radiated waves cancel each other out.

[0034] As will be explained below, such small size APG speakers are useful for achieving an acoustic nodal response (i.e., establishing quiet zones or pockets of silence (POS)) across a wide audible range.

[0035] FIG. 1 shows a schematic diagram of a sound suppression device 10 according to an embodiment of the present application. In the present application, the sound suppression device may also be referred to as an acoustic node terminal (abbreviated as ANT) capable of forming a local quiet zone or POS (wherein ANT and sound suppression device are used interchangeably in the present application). The sound suppression device 10 includes a sound sensing device (SSD, e.g., a microphone) 101 and a sound generating device (SPD) 102. The SSD 101 may be located near or adjacent to the SPD 102. The SSD is configured to detect sound S or noise N (a type of sound that is undesirable from a user's perspective). The SPD 102 may be realized by an APG device according to the teachings of 16 / 125,761, 17 / 553,806, and / or 18 / 321,759. The SPD can be considered to include an APG device. The APG device is configured to generate multiple air pulses UAP at an ultrasonic pulse rate. The multiple air pulses at the ultrasonic pulse rate form an anti-sound AS. Generally, the anti-sound AS comprises a sound component or anti-noise component AN, which is configured to suppress the unwanted noise N.

[0036] FIG. 20 shows the waveform of sound S, an image of reflected sound AS', and an image of ultrasonic air pulse UAP', where images AS' and UAP' represent or can represent the negatives of the reflected sound AS and ultrasonic air pulse UAP generated by the APG 102, which can be expressed as AS' = -AS and UAP' = -UAP. AS / AS' can be seen as the envelope or low-frequency component of UAP / UAP'. As can be seen from FIG. 20, within the quiet zone or POS, sound S is nearly canceled by the reflected sound AS and / or ultrasonic air pulse UAP. As a result, the magnitude of the residual sound S-AS' (or S+AS) or S-UAP' (or S+UAP) becomes too low to be discernible, or the frequency of the residual sound S-AS' (or S+AS) or S-UAP' (or S+UAP) becomes too high to be discernible.

[0037] In accordance with 18 / 321,759, FIG. 2 shows a schematic diagram of an APG device according to one embodiment of the present application. In this application, the APG device is designated 102. As shown in FIG. 2 (top), the APG device 102 has a film structure 12. As taught in 18 / 321,759, the film structure 12 is configured to perform a modulation operation to generate an ultrasonic acoustic / air wave UAW according to an audible sound signal ASS, and a demodulation operation to generate an ultrasonic pulse array UPA according to the ultrasonic acoustic / air wave UAW. The modulation operation is performed by common-mode movement of the film structure 12, and the demodulation operation is performed by differential-mode movement of the film structure 12. After the inherent low-pass filtering effects of the natural / physical environment and the human auditory system, a sound corresponding to the audible sound signal ASS is reproduced.

[0038] The film structure 12 has a pair of flaps 12p, which are operated to perform a common mode operation to perform a modulation operation, which generates an ultrasonic wave / air wave UAW, while the pair of flaps 12p are operated to perform a differential mode operation (or a differential operation for brevity) to perform a demodulation operation, which generates an ultrasonic pulse array UPA at an ultrasonic pulse rate (e.g., 72 KHz, 128 KHz, or 192 KHz) according to the ultrasonic wave / air wave UAW.

[0039] The flap pair 12p includes a first flap 12a and a second flap 12b disposed opposite each other, and is actuated to perform a differential mode operation to form the opening 112 at an opening rate that is synchronized with the ultrasound pulse rate.

[0040] The APG device 102 further includes a first actuator 14a and a second actuator 14b. The actuators 14a / 14b are disposed on the flaps 12a / 12b. Each of the actuators 14a, 14b includes an upper electrode and a lower electrode. The upper and lower electrodes receive a modulated signal SM and a demodulated signal +SV or −SV. In the embodiment shown in the lower part of FIG. 2, the upper electrodes of the actuators 14a and 14b receive the demodulated signals −SV and +SV, respectively, and the lower electrodes of the actuators 14a and 14b receive a (common) modulated signal SM. A bias voltage V BIAS are omitted here for simplicity. Demodulation signals +SV and −SV are applied to actuators 14a and 14b so that flap pair 12p performs differential action to form aperture 112. For details on the operating principles of APG device 102, see 18 / 321,759, which will not be described here for simplicity.

[0041] In one embodiment, the multiple ultrasonic air pulses or ultrasonic pulse array UPA that form the reflected sound AS may be propagated towards an open field, where reflection of the ultrasonic air pulses is negligible at the ANT 10. In one embodiment, the front face of the APG device 102 (the side from which the air pulses radiate) faces the periphery of the host device of the APG device 102. In one embodiment, the front face of the APG device 102 is positioned towards the periphery of the host device on which the APG device 102 is placed.

[0042] As mentioned above, in one embodiment, the APG device 102 is compact in size and can generate an SPL of 78±2 dB over a range of 10 Hz to 20 KHz (which covers almost the entire audible range), which is suitable for noise / sound suppression over a wide audible range.

[0043] Furthermore, the phase generated by the SPD / APG 102 is related to the pulse rate / cycle and propagation latency from the SPD to the SSD, regardless of various acoustic frequencies. In other words, the phase generated by the SPD / APG 102 is highly consistent. Therefore, the SPD / APG 102 is more suitable for noise / sound suppression compared to traditional speakers such as DD (dynamic drivers).

[0044] 1 , SSD 101 and APG device 102 may be connected to controller 16 via a wired or wireless link such as Bluetooth®. Controller 16 is configured to receive sound signal SS from SSD 101 and generate a control signal CS for APG device 102 to generate a plurality of air pulses at an ultrasonic pulse rate that form reflected sound AS. In one embodiment, control signal CS may include (de)modulated signals SM, ±SV, may be (de)modulated signals SM, ±SV, or may be used to generate (de)modulated signals SM, ±SV.

[0045] The operation of ANT 10 or controller 16 may be likened to / analogous to the operation of a negative feedback op-amp circuit (operational amplifier), such as system 30 shown in FIG. S corresponds to the incident sound pressure sensed by the SSD101, and V AS corresponds to the reflected sound pressure generated by the sound generator 102. S corresponds / related to the sound signal SS, and V AS may correspond / related to the control signal CS. For an ideal OP, where the open-loop gain g (e.g., g>>1,000) and phase remain near 0° over 1 MHz, the voltage at the negative input terminal of the OP, denoted as V- (following the virtual ground / short circuit principle of OP amps), approaches 0, i.e., V-≈0, V AS Conceptually, V S approaches the negative of V AS ≒-V SThus, the anti-sound AS suppresses / cancels the undesired sounds S or N (by ignoring the sensitivity of SSD 101 and amplifying the gain of SPD 102), and the system 30 processes sound waves with frequencies well above the 20 KHz upper limit of human hearing.

[0046] System 30 is configured to purely suppress undesired noise / sound, which can be extended to incorporate desired sounds. See system 32 shown in Figure 3. S / V S In addition to the system 30 where V represents the undesired sound / signal, the system 32 also includes a system 32 for detecting the desired signal V S1 and V S2 V, which can be considered the output of the controller 16 or the input of the APG device 102. AS 'V' AS =-R FB ×(V S / R S +V S1 / R S1 +V S2 / R S2 ) can be expressed as

[0047] Of course, system 32 can be easily modified to incorporate more desirable signals, V AS ' is V AS '=-R FB ×(V S / R S +V S1 / R S1 +...+V Sn / R Sn ), which means that when the loop gain of the system 32 is set high, the acoustic output generated by the SPD 102 will contain not only the sound component at −S (which is configured to suppress undesired sounds / noises), but also −(k1·S1,...,−k n Sn), where k n is R FB / R Snwhere S1,...,Sn represent the desired sounds. Note that the controller 16 may or may not include the op-amps shown in FIG.

[0048] In another aspect / embodiment, the operation of ANT 10 can be viewed as a feedback control loop. Figure 4 shows a system (or feedback control loop) 40 formed by ANT 10 and controller 16, according to one embodiment of the present application. In Figure 4, solid lines / arrows represent electrical paths and dashed lines / arrows represent acoustic paths. K represents the transfer function of the control block within controller 16. H P represents the transfer function of the SPD 102 (and the acoustic channel from the SPD 102 and the SSD 101). S represents the transfer function of SSD 101. W represents the acoustic disturbance or unwanted acoustic sound. Y represents the audio system output of system 40 or ANT 10, which is heard by the user. R represents the desired signal to be heard, V in FIG. S1 ..., V Sn It is similar to the integral of Y m represents the measurement / microphone output, and V in Figure 3 S or corresponds / similar to SS in Figure 1. E is R and Y m U represents the controller output, V in Figure 3. AS or corresponds / similar to the CS in Figure 1.

[0049] As a feedback control loop, the system output Y can be expressed as Y=T·R+S·W, where S can be considered as the sensitivity or noise transfer function of the feedback control loop 40, W represents the degree of damping, and S=1 / (1+H P K H S ) T can be considered as the closed loop transfer function or signal transfer function of the feedback control loop 40 and represents the degree to which R is perceived from Y, where T=H P K / (1+H P K H S) Within the band of interest (e.g., the audio band or the spectral band below 20 KHz), K is designed such that T→1 and S<<1.

[0050] ANT10 may be located / assembled within a wearable sound device, such as earphones or headphones, to create a local quiet zone or POS, where controller 16 may or may not be located within the wearable sound device. In one embodiment, controller 16 may be located within an electronic device that has a wireless connection with the wearable sound device, with ANT10 located within it.

[0051] See Figures 5 and 6 for this type of application. Under this application scenario, the ability of each individual ANT to create a local POS via reflected sound is utilized to create a local POS within a radius of r = λ / 2π for sound of wavelength λ. For example, in the configuration 52 of Figure 5, ANT 10 is placed at or outside the outer opening of the ear canal, which for an adult is a semi-ellipse with a diameter of 8-10 mm. A wearable sound device holder 508, which may be made of a material such as silicone or any suitable material, can hold ANT 10 near or centered at the entrance of the ear canal, as shown at 506 and 507, where 507 represents the cross section of the ear canal and 506 represents the passageway within the ear canal. The effective upper frequency limit for the POS created by ANT 10 of Figure 5 is 346 / (4.5 x 10 -3 × 2π) = 12.24 KHz (by assuming a radius of the outer opening of the ear canal of 4.5 mm), which is sufficient to suppress most environmental noise.

[0052] Furthermore, as an embodiment, the dimensions of the ANT are 2.5 x 4.6 x 8 mm 3 Assuming that the percentage of the area of ​​the ear canal 506 / 507 blocked by the ANT10 is effectively (2.5 × 4.6) / (4.5 2× 2π) ≈ 18%, which means that a good design of the holder 308 can open up to 80% of the ear canal passage 306, which allows airflow in and out of the ear canal and helps to avoid causing discomfort during long periods of wear, such as sleeping for 8 hours or more.

[0053] By combining these two features (POS up to 12KHz effective frequency; minimal / no discomfort) with appropriate environmental control, ANT10 can be placed in device 52 with nighttime ambient noise control. Device 52 can also be applied in any situation where quiet, restful privacy is desired with minimal / no discomfort during prolonged wear.

[0054] Due to safety concerns, the controller 16 may be optimized for the intended virtual quiet zone application. For example, the controller 16 in the ANT 10 may manually or automatically enter an "ambient passthrough" mode to allow ambient sounds to be heard by the user. The ambient passthrough mode may be enabled by the R S This can be achieved by adjusting the RMS power, adjusting the sensitivity S of the closed-loop feedback control system 40, or by (partially) including ambient sounds in the desired signal R shown in Figure 4. In one embodiment, the ANT 10 can sense (ambient) buzzers or warning sounds and automatically enter ambient pass-through mode. Additional control signal(s) can be added to enable personal electronic devices such as smartphones / watches to perform emergency notifications or AI (artificial intelligence) tuning of the device via wireless or BT.

[0055] As shown in Figure 6, ANT10, which creates a local POS or small quiet zone, can be applied to all kinds of earphones (e.g., 61, 62) and headsets (e.g., 63, 64). Note that, unlike traditional ANC technology in audio applications, sound suppression / cancellation is performed in the open field. In Figure 5 or Figure 6, one or more ANT10 create a "virtual quiet zone" near the entrance of the ear canal, such as near the tip of the ear, so that most environmental noises are canceled by the reflected sound generated by the ANT / APG before they have a chance to enter the ear canal.

[0056] It should be noted that the location of the ANT on the wearable sound device is not limited and can be optimized according to actual requirements.

[0057] In other words, unlike conventional ANCs that generate reflected sound inside the ear canal, ANT10 generates reflected sound via its own speaker 102 located outside the ear canal, and ANT10 performs sound suppression / cancellation in the open field. Because the SPD 102 is placed outside the ear canal, the reflected sound generated by the SPD 102 cancels out ambient sound waves, which ideally results in net-zero residual ambient noise entering the ear canal. That is, by creating a localized pocket of silence by generating reflected sound, ambient noise is canceled before it reaches the ear tip of the earphone, thus avoiding the need to cancel noise after it enters the ear canal. Furthermore, ANT10 operates in the open field, before ambient sound passes through passive isolation and is disrupted or contaminated by resonances within the ear canal.

[0058] 1, the controller 16 may optionally include, but is not limited to, a filter 167. In one embodiment, the filter 167 may be configured to adjust the frequency response of the control signal CS to customize the effective frequency range of the reflected sound generated by the ANT 10. For example, the filter 167 may impose low-pass filtering or band-rejection (notch filtering) on ​​the reflected sound.

[0059] In one embodiment, the controller 16 may be coupled to the SSD 708 as shown in Figure 7. In Figure 7, since the ANT 10 is worn / placed in the ear, the SSD 708 may be worn facing the user's mouth, which may be used to capture / sense sound. S1 (Here, V in Figure 3 S2 An audio signal VS sensed by the SSD 708, which corresponds / similar to (for example, corresponds to a music file to be played), may be sent to the controller 16 so that the SPD 102 may generate audio corresponding to the audio signal VS, which may be (part of) the ambient pass-through sound / signal to be heard.

[0060] The placement of SSD 101 and SPD 102 is not limited. In one embodiment, as shown in Figure 8, ANT 10 may be placed on / in a wearable sound device (e.g., OWS (Open Wearable Stereo) earphones) such that SPD 102 is placed outside the ear canal, while SSD 101 is placed inside the ear canal. In this case, the user may have an acoustically transparent and occlusion-free experience (around), which improves the user experience.

[0061] Because the diameter of the ear canal (typically 5-6 mm) is much smaller than the wavelength of audible sound, an audible sound wave after propagating into the ear canal can be seen (or forced) as a plane wave, even if it was a spherical sound wave before entering the ear canal. Placing the SSD 101 inside the ear canal can bypass / reduce the effect of the 1 / r propagation attenuation of the (spherical) sound wave generated by the SPD 102, allowing for accurate capture of sound / noise.

[0062] In one embodiment, the SSD 101 (sensing hole) can be positioned in the ear canal so that it has a distance (from the outer ear to the ear canal transition surface) within the ear canal, which is (1 / 3) × φ 外耳道~ 1×φ 外耳道 and φ 外耳道 represents the diameter of the ear canal. 外耳道 Assuming that the distance is 12 mm, in one embodiment, the SSD 101 (sensing hole) may be (substantially) 2 to 6 mm inside the ear canal.

[0063] When ANT10 is placed within a wearable sound device such as an OWS earphone, the SPD / APG 102 can perform not only noise suppression operations to suppress unwanted sounds such as noise, but also sound generation operations to generate desired sounds such as music. Note that ANT10 embedded within an OWS earphone achieves a near "full-on" or "full ambient pass-through" mode when the noise suppression operations of ANT10 or SPD 102 are turned off (although sound generation operations may remain functional). In other words, the ultimate ambient pass-through mode can be achieved by simply pausing the noise suppression operations.

[0064] The effective bandwidth of noise suppression is d AS The larger the effective bandwidth, the shorter the required distance d AS In one embodiment, the distance d AS may be less than the wavelength corresponding to the maximum frequency of the noise desired to be suppressed. For example, the distance d ASThe wavelength of the noise desired to be suppressed may be less than 5.77 mm, which is the wavelength corresponding to 20 KHz (the maximum frequency of the noise desired to be suppressed), but is not limited to this. The maximum frequency of the noise desired to be suppressed may be 7 KHz (which covers most of the human voice band), and AS may be less than 50 mm or may be 16 KHz (which covers the upper limit of audible frequencies for most adults over 35 years old), and d AS may be less than 22 mm.

[0065] The frequency f (related to the effective bandwidth) is

number

[0066] Referring again to FIG. 4, when the SSD 101, the SPD 102, and the controller 16 form a feedback control loop 40, the feedback control loop 40 has a loop gain L (L=H P K H S ) or the open-loop gain g OL (g OL =H PGenerally, the band of interest (H S →1) the residual error decreases as the loop gain increases.

[0067] In one embodiment, the loop gain g OL / L can be adjusted (automatically) to be higher in noisy environments and lower in quiet environments.

[0068] That is, the loop gain g OL / L may be increased when the ambient / environmental SPL is large or increases, and vice versa. The ambient / environmental SPL may be measured by an SSD, which may or may not be SSD 101.

[0069] In other words, the controller 16 may perform an adaptive gain control (AGC) operation. The controller 16 may receive the ambient SPL and adjust the corresponding loop gain g for the feedback control loop 40 according to the ambient SPL. OL In one embodiment, the loop gain g OL / L is adjusted higher. Or equivalently, the controller 16 adjusts the loop gain g OL / L can be lowered.

[0070] The AGC adjustment scheme can be shown in Fig. 9(a). As shown in Fig. 9(a), when the ambient SPL is greater than or equal to the threshold SPL L-th and SPL H-th When the ambient SPL is between 0.05 and 0.15, the loop gain can be increased as the ambient SPL increases. H-th When it is larger than g max and the environmental SPL is set to SPL L-th When g is smaller than min In one embodiment, the environmental SPL may be set to a certain SPL threshold (e.g., SPL L-th ), sound suppression may be turned off. In other words, in order to reduce / minimize power consumption, some amplifier circuits (especially the loop gain g OL / L), or even the SPD 102, can be turned off.

[0071] In one embodiment, the SPL L-th may be 33 dB, 3 dB higher than 30 dB, which corresponds to the SPL level of a whisper in the ear; SPL H-th may be, but is not limited to, 52 dB, which is 2 dB higher than 50 dB corresponding to the SPL level of soft conversation.

[0072] Furthermore, an important goal of the AGC in adjusting the loop gain is to maintain the residual noise level below a threshold appropriate for the intended application, for example, but not limited to, 35-45 dB for sleep, 50-55 dB for awake activity, and 60-65 dB for adequate ambient awareness.

[0073] Additionally, the controller 16 may include a latency t adj Adjustable latency t adj may include the response time of the AGC adjustment. In general, the controller 16 will adjust the AGC faster (smaller t adj in quiet environments and slower (larger t adj (in) latency to respond adj In other words, the controller 16 may adjust the latency t according to the environmental SPL. adj In one embodiment, the higher the ambient SPL, the lower the latency t adj is adjusted lower.

[0074] Furthermore, in one embodiment, the AGC adjustment may respond faster when the ambient environment is or becomes noisier compared to scenarios in which the ambient environment is (or becomes) quieter.

[0075] For example, Figure 9(b) shows a latency adjustment scheme according to one embodiment of the present application. The controller 16 determines whether the ambient SPL (as sensed by the SSD 101) is equal to or greater than the SPL L,1Louder SPL H,1 When the latency is less than t adj , and the ambient SPL (which may be sensed by SSD 101) may be controlled to reduce SPL H,2 Lower SPL L,2 When the latency is greater than t adj In one embodiment, an optional hysteresis for the latency adjustment may be included, which increases with increasing SPL H,2 >SPL H,1 and SPL L,2 >SPL L,1 The hysteresis can prevent up and down oscillation of the loop gain adjustment, which can stabilize the loop operation of ANT10. L,1 ,SPL L,2 ,SPL H,1 ,SPL H,2 ) can be (27 dB, 33 dB, 52 dB, 65 dB), which can be designed according to practical requirements, but is not limited to these. In one embodiment, the values ​​in FIG. min About 1~10dB, g max About 30~600dB, t min 10 to 100 μS (microseconds) and t max The time may be selected from, but is not limited to, 1 to 200 mS (milliseconds).

[0076] Note that SPL here refers (by way of example only) to a measurement of the acoustic volume of an environment, but is not limited to this, and any type of acoustic measurement can be applied to the AGC and latency adjustments described above.

[0077] Furthermore, the concept of establishing quiet zones or POS can be extended to achieve acoustic insulation or acoustic reflection through multiple / multiple sound suppression devices that can be placed in a certain pattern or regularity.

[0078] FIG. 10 shows a schematic diagram of sound suppression systems 90a and 90b according to embodiments. The sound suppression systems 90a / 90b include a plurality of sound suppression devices (e.g., sound suppression devices 10 having SSDs and SPDs) indicated by shaded circles in FIG. 10. The plurality of sound suppression devices may be arranged in a one-dimensional array, as in system 90a, or in a two-dimensional array, as in system 90b, but are not limited thereto. The sound suppression devices may be arranged in a d NN In one embodiment, the sound suppression device may have a specific pattern, e.g., a spacing between ANTs of d, as in system 90b. NN The electrodes may be arranged in, but are not limited to, an equilateral triangular pattern having a

[0079] Multiple sound suppression devices may also be arranged as a circular array (e.g., arranged on noisy machinery such as an MRI (Magnetic Resonance Imaging) machine or a drone, which may be arranged at equal or uneven intervals), or as a three-dimensional array. As long as the arrangement of the sound suppression devices can effectively suppress undesired sounds / noises, it is within the scope of the present invention.

[0080] In one embodiment, multiple sound suppression devices (in sound suppression system 90b) may be physically connected via some connecting structure, such as string / cord / rope, to form a meshed network. The meshed sound suppression system may be in the form of a curtain or screen that is highly permeable to light and / or airflow, for example, greater than 60% permeable to light and / or airflow. In this application, permeable to light and / or airflow means greater than 50% permeable to both light and / or airflow.

[0081] It should be noted that the SPD of the sound suppression device in the sound suppression system is not limited to the APG device described above. As long as the sound suppression device is arranged in a specific pattern, such as an array or mesh, and provides some degree of acoustic insulation / reflection, it is within the scope of this application. Preferably, the SPD of the sound suppression device has a compact size and is capable of generating sound across the full audible bandwidth at a substantial SPL, which is suitable for the configuration of the sound suppression device / system. Furthermore, generating SPD and carrying consistent phase is also beneficial for noise suppression.

[0082] 11 shows a schematic diagram of an embodiment / application 91 of a sound suppression system applied to an acoustic (insulating) screen. In embodiment / application 91, a sound suppression system 90b is configured to form acoustic (insulating) screens 911 and 915. Acoustic screen 915 may have a lower density of sound suppression devices (this is due to the spacing d between the ANTs of acoustic screen 915). NN is the distance d between the ANTs of the acoustic screen 911 NN means greater than.

[0083] The acoustic (insulating) screen 911 / 915 is configured to suppress sound on one side of the screen 911 / 915 and is intended to prevent sound from one side of the screen 911 / 915 from propagating to the other side. That is, the screen 911 / 915 is configured to attenuate / suppress a first sound from a first sound source in a first subspace on a first side (e.g., the right side) of the screen 911 / 915. The first sound may propagate through the screen 911 / 915 toward a second subspace on a second side. After the first sound passes through the screen 911 / 915, which is permeable to light and / or airflow, the suppressed first sound propagates toward the second subspace on the second side (e.g., the left side) of the screen 911 / 915, and the acoustic magnitude of the suppressed first sound is significantly smaller (e.g., 10 dB lower, or at least 3 dB lower) than the acoustic magnitude of the first sound. Here, loudness may refer to SPL, sound pressure, sound intensity, etc., or any sound measurement that describes the strength of an acoustic sound.

[0084] Construction 91 may further optionally include curtains 912 and 913. Curtains 912 and 913, which may be made of cloth or cloth-like material, may be positioned on first and second sides of screen 915 and may provide and assist in higher frequency sound absorption so that the strength of the sound suppression device density and manufacturing costs of screen 915 may be reduced. Additionally, upper screen 911 may have a higher density for acoustic insulation over an extended (higher) frequency range.

[0085] The structure 91 can be used in medical applications, for example in hospital wards or clinics, to divide the space of a room when privacy is required. In addition to being interchangeable for reasons of cleanliness and hygiene, which are important in medical applications, the fabric curtains 912 and 913 can also serve as sound dampeners. The presence of sound-absorbing material in the small chambers will contribute to comfort.

[0086] 12 shows a schematic diagram of one embodiment / application 92 of a sound suppression system that may be applied to form an acoustically isolated space. The sound suppression system(s) 90b may be embedded within an acoustic insulating screen 920. The acoustic insulating screen 920, which may be portable, forms / encloses a space / room 922. The space / room 922 may be acoustically isolated.

[0087] A space / room 922 may be established for privacy, which may be used, for example, as a conference room in an office, or for hosting (backyard) parties with family / friends, or some construction (e.g., partial renovation of floor tiles in an apartment) that occupies a small area but generates a lot of noise may be carried out within the (nomadic) space / room 922.

[0088] An acoustically insulated space or private space in this application may refer to a space that confines internal conversations (or other types of sounds within the space) and substantially blocks internal conversations (or other types of sounds) from propagating to the outside. An acoustically insulated space or private space in this application may also refer to a space that does not allow external noise / sound to enter, which substantially blocks external noise / sound from propagating to the inside.

[0089] FIG. 13 shows a schematic diagram of an office scenario as an application 93 of a noise suppression system according to an embodiment of the present invention. The sound suppression system(s) 90b can be embedded inside acoustic insulating screens 930L, 930R, and 930F, which can be permeable to airflow and / or light. The acoustic insulating screens 930L, 930R, and 930F can be used as cubicle partitions. Take cubicle 932 as an example. The cubicle 932 is surrounded by a left screen 930L, a right screen 930R, and a front screen 930F. Due to the high permeability to airflow, the ambient atmosphere of the office still retains that of an open office, allowing the free exchange of ideas to take place unhindered. However, the employed screens 930L, 930R, and 930F allow for the creation of private workspaces on the spot whenever concentration and focus are needed.

[0090] FIG. 14 shows a schematic diagram of an aircraft cabin scenario as an application 94 of a sound suppression device / system according to one embodiment of the present invention. The sound suppression device 940 may be placed on the sidewall of the aircraft cabin. The noise spectrum inside the aircraft cabin may have peak(s) occurring between 40 and 60 Hz, corresponding to a wavelength λ of 8.6 m (meters) to 5.8 m, with half the wavelength λ / 2 being between 2.9 m and 4.3 m, corresponding to a cabin width of, for example, 3.63 m. In other words, placing the sound suppression device on the sidewall(s) of the aircraft cabin may effectively nullify or reduce cabin resonant noise, improving passenger flight experience.

[0091] 15 shows a schematic diagram of a construction site scenario as an application 95 of a sound suppression system according to one embodiment of the present invention. Sound suppression system(s) 90b may be embedded inside an acoustic insulating screen 950. Construction noise generated within the building is suppressed / insulated by the acoustic insulating screen 950, thereby making the neighborhood of the construction site rather quieter than it would be without the acoustic insulating screen.

[0092] 16 and 17 show schematic diagrams of residential space scenarios as applications 96 and 97 of sound suppression systems according to embodiments of the present invention. For the interior space 967 of the residential space 96, the sound suppression system may be installed between drywall (e.g., structures 962 / 964), under the ceiling (e.g., structure 961), or inside the floor (e.g., structure 965). For the patio 968, the sound suppression system may be formed as an acoustic screen and placed at location / window 963 or location / entrance 966, which keeps outside noise out and occupants' private conversations out. For the residential space 97, the sound suppression system may be in the form of a screen (e.g., 971, 972, 973, 976, for blocking outside noise) or a curtain (e.g., 974, 975, for dividing functional spaces).

[0093] Additionally, the sound suppression device(s) within the sound suppression system may perform the loop gain and / or latency adjustments described above, particularly if the sound suppression system consumes significant power. 2 (square meters), effective noise suppression bandwidth (d NN = 4cm and 1,440 ANT / m 2 For an acoustic insulation screen application to a patio (which may require a density of 100 Watts), assuming each ANT consumes 0.87 mW (milliwatts), the total power consumption would be 100 W (watts). Therefore, it may be desirable to make the loop gain adjustments described above to power the total power consumption.

[0094] 18 shows a schematic diagram of a seating scenario as an application 98 of a sound suppression device according to one embodiment of the present invention. The sound suppression device 980 may be placed in a seat in a vehicle such as a car, train, bus, plane, ferry, etc.

[0095] 19 shows a schematic diagram of a sound wall scenario as an application 99 of a sound suppression system according to one embodiment of the present invention. The sound suppression system 90b may be placed on a sound wall 991. Unlike a conventional sound wall, which may be a physical blockage with no active sound source to the left of the physical blockage and where diffraction effects occur along the edges of the physical blockage, the sound wall 991 is an active sound counter and has sound suppression devices that may eliminate diffraction effects.

[0096] It should be noted that edge diffraction may be the main reason why noise barriers generally must be very tall, and that noise barriers are generally only marginally effective at suppressing highway noise and are not commonly used at suppressing airport or railroad noise.

[0097] The benefit of having no edge diffraction is shown in Figure 18, where path 993 represents the path that sound waves would travel if there was edge diffraction, and path 992 represents the path that sound waves would travel if there was no edge diffraction. If sound barrier 991 has sound suppressors, the sound waves along diffraction path 993 are weaker, which not only reduces the required height of the sound barrier, but also reduces the effective noise (reaching the occupied building).

[0098] Typically, multiple sound suppression devices / systems are placed in noisy environments, such as construction sites, bullet train stations, airport runways, walkways or roads, aircraft cabins, and aircraft carrier decks, including by noisy machinery such as military tanks, MRI (magnetic resonance imaging) machines or drones.

[0099] In summary, a sound-generating device that has a compact size and is capable of generating sound over the full audible bandwidth is suitable for noise / sound suppression. Multiple sound suppression devices arranged in a specific pattern can form a sound suppression system or an acoustic insulating screen, which can provide acoustic insulation but be permeable to light and / or airflow, enhancing privacy or the quality of human life.

[0100] Those skilled in the art will readily appreciate that numerous modifications and variations of the apparatus and method may be made while retaining the teachings of the present invention. Accordingly, the above disclosure should be construed as limited only by the scope and spirit of the appended claims.

Claims

1. 1. A sound suppression device, comprising: a sound sensing device configured to sense sound; and a sound generating device having an air pulse generating device configured to generate a plurality of air pulses at an ultrasonic pulse rate; and the plurality of air pulses at the ultrasonic pulse rate form echoes; The sound-reducing device includes a component configured to suppress the sound; The air pulse generating device comprises: a film structure having a flap pair having a first flap and a second flap disposed opposite each other; a first actuator disposed on the first flap and a second actuator disposed on the second flap; the pair of flaps are actuated by the first actuator and the second actuator to perform differential mode motion to form an aperture at an aperture rate synchronized with the ultrasonic pulse rate; Sound suppression device.

2. the sound sensing device and the sound generating device are coupled to a controller; the controller is configured to receive a sound signal from the sound sensing device and generate a control signal for causing the air pulse generating device to generate the plurality of air pulses at the ultrasonic pulse rate that forms the reflected sound. The sound suppression device of claim 1 .

3. the controller having a filter configured to adjust the frequency response of the reflection; The sound suppression device of claim 2 .

4. the dimensions of the air pulse generating device are less than a wavelength corresponding to a maximum noise frequency of the noise to be suppressed; The sound suppression device of claim 1 .

5. There is no back enclosure located on, beside, or under the rear of the air pulse-generating device; The sound suppression device of claim 1 .

6. the distance between the sound sensing device and the air pulse generating device is less than a wavelength corresponding to the maximum frequency of the noise to be suppressed; The sound suppression device of claim 1 .

7. The sound suppression device is incorporated into a wearable sound device. The sound suppression device of claim 1 .

8. The sound sensing device is disposed within the wearable sound device such that, when the wearable sound device is worn, a sensing hole of the sound sensing device faces the user's ear canal; the sound generating device is positioned outside the ear canal when the wearable sound device is worn; 8. The sound suppression device of claim 7.

9. the plurality of air pulses forming the echoes propagate toward an open field; a front surface of the air pulse generating device is positioned toward the periphery of the host device of the air pulse generating device; The sound suppression device of claim 1 .

10. the sound sensing device and the sound generating device are coupled to a controller; the sound sensing device, the sound generating device and the controller form a feedback control loop; The controller adaptively adjusts a loop gain or latency of the feedback control loop. The sound suppression device of claim 1 .

11. the controller adjusting the loop gain or the latency of the feedback control loop according to acoustic measurements of the environment.

11. The sound suppression device of claim 10.

12. the controller adjusts the loop gain to be lower when the acoustic measurements of the environment are lower; 12. A sound suppression device according to claim 11.

13. the controller adjusts the latency to decrease when the acoustic measurements of the environment increase; the controller adjusts the latency to be larger when the acoustic measurements of the environment are lower; 12. A sound suppression device according to claim 11.

14. Hysteresis is included when the controller performs the latency adjustment.

12. A sound suppression device according to claim 11.

15. 1. A sound suppression system comprising: a plurality of sound suppression devices arranged in an array; one of the plurality of sound suppression devices having a sound sensing device configured to sense sound and a sound generating device configured to generate reflected sound; the counter-sound is configured to suppress the sound; the sound generating device includes an air pulse generating device configured to generate a plurality of air pulses at an ultrasonic pulse rate; the plurality of air pulses at the ultrasonic pulse rate form the echo; The air pulse generating device comprises: a film structure having a flap pair having a first flap and a second flap disposed opposite each other; a first actuator disposed on the first flap and a second actuator disposed on the second flap; the pair of flaps are actuated by the first actuator and the second actuator to perform differential mode motion to form an aperture at an aperture rate synchronized with the ultrasonic pulse rate; Sound suppression system.

16. the sound suppression device is arranged to form an acoustic screen; 16. The sound suppression system of claim 15.

17. The acoustic screen is transparent to light or airflow.

17. The sound suppression system of claim 16.

18. The acoustic screen is used to create a private space.

17. The sound suppression system of claim 16.

19. the plurality of sound suppression devices or the sound suppression system are positioned near or at a seat in a noisy environment; 16. The sound suppression system of claim 15.

20. the physical dimensions of the sound-generating device are less than 20 mm (millimeters); 16. The sound suppression system of claim 15.

21. 1. A method of acoustic insulation comprising: forming an acoustic insulating screen, the acoustic insulating screen comprising the sound suppression system of claim 15; placing the acoustic insulating screen within the space; Including, the acoustic insulating screen divides the space into a first subspace and a second subspace; a first sound coming from the first subspace is suppressed by the acoustic insulating screen, and a suppressed first sound corresponding to the first sound propagates toward the second subspace; the acoustic loudness of the suppressed first sound is smaller than the acoustic loudness of the first sound; Acoustic insulation methods.

22. 1. A method for noise suppression comprising:

16. The sound suppression system of claim 15, comprising placing the plurality of sound suppression devices in a noisy space or near a noisy machine or in a seat. Noise suppression methods.

23. 1. A method for creating a private space, comprising:

22. The method of claim 21, comprising: positioning one or more acoustic insulating screens formed by the acoustic insulation method of claim 21 to form the private space enclosed by the one or more acoustic insulating screens. method.

24. 1. A method of acoustic insulation comprising: forming an acoustic insulating screen, said acoustic insulating screen being permeable to air flow; placing the acoustic insulating screen within the space; Including, the acoustic insulating screen divides the space into a first subspace and a second subspace; a first sound coming from the first subspace is suppressed by the acoustic insulating screen, and a suppressed first sound corresponding to the first sound propagates toward the second subspace; the acoustic loudness of the suppressed first sound is less than the acoustic loudness of the first sound; the acoustic insulating screen having an air pulse generating device configured to generate a plurality of air pulses at an ultrasonic pulse rate; the plurality of air pulses at the ultrasonic pulse rate form echoes; the counter-sound includes a component configured to suppress the first sound; The air pulse generating device comprises: a film structure having a flap pair having a first flap and a second flap disposed opposite each other; a first actuator disposed on the first flap and a second actuator disposed on the second flap; the pair of flaps are actuated by the first actuator and the second actuator to perform differential mode motion to form an aperture at an aperture rate synchronized with the ultrasonic pulse rate; Acoustic insulation methods.

25. the acoustic insulating screen is transparent to light; 25. The acoustic insulation method of claim 24.

26. A wearable sound device comprising: a sound sensing device configured to sense sound; and a sound generating device configured to generate a reflected sound, the reflected sound including a component configured to suppress the sound; and the sound generating device that generates the reflected sound is located outside the ear canal when the user wears the wearable sound device; the sound generating device includes an air pulse generating device configured to generate a plurality of air pulses at an ultrasonic pulse rate; the plurality of air pulses at the ultrasonic pulse rate form the echoes; The air pulse generating device comprises: a film structure having a flap pair having a first flap and a second flap disposed opposite each other; a first actuator disposed on the first flap and a second actuator disposed on the second flap; the pair of flaps are actuated by the first actuator and the second actuator to perform differential mode motion to form an aperture at an aperture rate synchronized with the ultrasonic pulse rate; Wearable sound device.

27. the sound sensing device is in the ear canal of the user when the user wears the wearable sound device; 27. A wearable sound device according to claim 26.

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